Hello MissWitch2310,
After reviewing your post, it seems like you received a new iPad and suddenly a gray line has appeared vertically across the height of the screen. Since you can still tap on stuff it may not be an iOS issue, but a hardware issue. There are a couple things you can try that may be able to help.
Does the line stay there on every screen and using every app?
If the screen isn’t working on your iPhone or iPad
iPad Repair
Please don't hesitate to let us know if the steps resolved your issue or if you need additional assistance.
Thank you for using Apple Support Communities. Have a nice day.